Pyrolysis gas chromatography is an important chemical analysis method. According to this method, a specific substance to be analyzed is decomposed by heating to generate a number of decomposition products which are then determined by gas chromatography.
In this pyrolyzing chromatography, in the case where the specific substance to be analyzed is accompanied by other volatile substance, if this mixture sample is heated at a temperature lower than the pyrolyzing temperature of the specific substance to volatilize the volatile substance, the volatile substance is analyzed by the gas chromatography if necessary and the sample is then heated at the pyrolyzing temperature and the intended pyrolyzation is carried out, the pyrolyzing chromatography of the specific substance can be precisely performed and the accompanying other substance can be simultaneously analyzed. Therefore, the method will be very convenient and advantageous.
However, an appropriate apparatus for carrying out this method has not been known.
There is known an apparatus comprising only a heater for pyrolyzing sample components. However, when this apparatus is used, it is impossible to separate a volatile component by volatilization before the pyrolyzation of the intended substance. Furthermore, there is known an apparatus of the type where a heater for the pyrolyzation is placed in a heating block preheated at 200.degree. C. to 300.degree. C. When this apparatus is used, a sample is inserted into the heating block in the state where the heater for the pyrolyzation is not actuated, a volatile component is volatilized at a temperature lower than the pyrolyzing temperature by heating by the heating block and the volatile substance is analyzed, and then, the heater for the pyrolyzation is actuated to perform the pyrolyzation of the sample and the pyrolyzation products are analyzed. However, this method is still insufficient in the following point. During a relatively long period of from the point of completion of the volatilization of the volatile component to the point of termination of the analysis of the volatile component by the gas chromatography, for example, during a period of 20 to 40 minutes, the sample is kept exposed to the temperature of the heating block, and especially if air is incorporated into a carrier gas passage at the time of charging of the sample, an undesirable reaction of the sample, such as oxidation, is advanced and precise analysis becomes difficult.